City States which let you build Unique Units

[WitchyStella]

Hi there! I've recently started to do some planning on a mod that adds city states that let you build other civs' unique units. This idea was inspired by Gedemo's city state mods, some of which do exactly this.
I'm planning to add a small secondary bonus as well, since the units are generally either only viable for one era or get unlocked late into the game.
I am looking for some suggestions and criticism, especially concerning balance since this will be my first larger scale mod and I don't have any experience when it comes to balancing.
I've done a fair amount of research into these and some were difficult since obviously the civs' unique units are unique to those civilizations/countries most of the time - in some cases I ended up deciding to use a name that was already included in the civ's city list just because I couldn't find a better fit. Some are areas rather than cities and some are historical names for existing cities - this is obviously not ideal. I know the community is very diverse and/or well informed about different historical and cultural topics, so I'm hoping you all can help me in finding better fitting alternatives where necessary!

Here are the ideas so far:

Sarepta;

trade/maritime (with CIVITAS City-States Expanded)
unlocks the bireme, +1 faith from mines & quarries​

Malinalco;

religious
unlocks the eagle warrior, +2 tourism from temples​

Wînipâkw;

trade
unlocks the okihtcitaw, +1 prod from fishing boats & camps​

Dongola;

trade
unlocks the pitati archer, +1 trade route per encampment​

Sønderborg;

industrial
unlocks the longship, +1 prod/universits, +1 science/factory​

Nagar;

industrial/consular
unlocks the war-cart, horses count as luxury​

Aegeae;

cultural
unlocks the hetairoi, +2 culture per holy site​

Vergina;

cultural
unlocks the hypaspists, +2 tourism per holy site​

Ecbatana;

militaristic
unlocks the immortal, +50 outer defense strength per wall level​

Anziku Nziku;

trade
unlocks the ngao mbeba, +1 gold for mines & quarries​

Dahestan;

militaristic
unlocks the saka horse archer, +50% prod towards cavalry​

Te Papa-i-Oea;

cultural/maritime
unlocks the toa, +2 culture from whales​

Chellah;

trade/maritime
unlocks the barbary corsair, +50% prod towards naval raiders​

Bjornheim;

militaristic/maritime
unlocks the berserker, +1 food on snow​

Poděbrady;

cultural/entertainment
unlocks the black army, +1 culture from rivers​

Nanjing;

cultural
unlocks the crouching tiger, +50% prod towards walls​

Arimaddana Pura;

trade
unlocks the domrey, +50% prod towards holy site buildings​

Mantyasih;

religious
unlocks the jong, +2 tourism from temples​

Shatili;

militaristic
unlocks the khevsur, melee units gain +5 strength on hills​

Gao;

trade
unlocks the mandekalu cavalry, +2 gold from horses​

Heian-kyō;

trade
unlocks the samurai, +1 food from rivers and canals​

Ch'iyar Jaqhi;

militaristic
unlocks the warak'aq, +2 culture from arenas​

Orsza;

religious
unlocks the winged hussar, faith thermopylae​

Värmland;

cultural
unlocks the carolean, +1 gpp from theater square buildings​

Haragona;

cultural
unlocks the conquistador, +2 culture from temples​

Lelystad;

cultural
unlocks the de zeven provinciën, +2 culture from floodplains​

Kaesong;

militaristic
unlocks the hwacha, ranged units gain +5 strength​

Edirne;

religious
unlocks the janissary, +2 tourism from worship buildings​

Curalaba;

militaristic
unlocks the malon raider, +5 strength for cavalry​

Plymouth;

trade/maritime
unlocks the sea dog, +1 gold from rivers​

Dikoye Polye;

militaristic
unlocks the cossack, cavalry can capture defeated enemy units​

Ajaccio;

trade/maritime
unlocks the garde impériale, -1 unit maintenance​

Perth;

militaristic/consular
unlocks the highlander, +2 loyalty on foreign continents​

Belgrade;

cultural
unlocks the huszar, +2 great artist points per theatre square​

Newcastle Upon Tyne;

scientific/maritime
unlocks the minas geraes, +2 gold per uni, +2 science per harbor​

Edge Hill;

industrial
unlocks the redcoat, +2 gold from mines​

Oklahoma;

industrial/agricultural
unlocks the rough rider, +2 gold from oil improvements​

Wellington;

trade
unlocks the digger, +2 gold from research centers​

Yellowknife;

trade
unlocks the mountie, +2 gold from mines​

Kiel;

militaristic/maritime
unlocks the u-boat, +50% production towards naval raiders​

Centinela Springs;

religious/agricultural
unlocks the p-51 mustang, +1 faith from rivers​